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1.
Dig Dis Sci ; 69(3): 749-765, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38217680

RESUMO

BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) that contributes in part to irreversible bowel damage and long-term complications, reduced quality of life, invalidity, and economic burden. Suboptimal control of IBD is associated with higher healthcare resource utilization (HCRU), impaired quality of life (QoL), and reduced work productivity. AIMS: The IBD-PODCAST study aimed to assess the proportion of IBD patients with suboptimal control and its associated impact. METHODS: IBD-PODCAST is a cross-sectional, multicenter study that aimed to characterize the CD and UC population with optimal or suboptimal control according to the STRIDE-II criteria and patient- and physician-reported measures. Here we present the results of the Spanish cohort (n = 396). RESULTS: A total of 104/196 (53.1%) CD and 83/200 (41.5%) UC patients were found to have suboptimal disease control. Long-term treatment targets according to STRIDE-II were applied in 172 (87.8%) CD and 181 (90.5%) UC patients. 125 of 172 (72.7%) CD and 74 of 181 (40.9%) UC patients were currently treated with targeted immunomodulators. Patients with CD and UC and suboptimal disease control showed impaired QoL, higher HCRU and direct costs, and also loss of work productivity compared to those with optimal control. CONCLUSION: Despite a high rate of targeted immunomodulator therapy, a substantial proportion of IBD patients show suboptimal disease control according to the STRIDE II criteria. Those patients with suboptimal disease control exhibit impaired QoL, less work productivity, and higher HCRU, suggesting that there is considerable need for better treatment approaches in IBD.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Qualidade de Vida , Espanha/epidemiologia , Estudos Transversais , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/epidemiologia , Doença de Crohn/diagnóstico , Doença de Crohn/tratamento farmacológico , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/tratamento farmacológico , Fatores Imunológicos/uso terapêutico
2.
Aliment Pharmacol Ther ; 34(5): 544-54, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21722149

RESUMO

BACKGROUND: Low thiopurine-methyl-transferase (TPMT) activity and high 6-thioguanine-nucleotide (6TGN) concentrations have been linked to therapeutic success in inflammatory bowel disease patients treated with thiopurines; however, this has not been implemented in clinical practice. AIM: To identify a therapeutic threshold value for TPMT or 6TGN concentrations, and their capability to predict treatment safety and efficacy. METHODS: Prospective multicentre study including steroid-resistant/dependent patients starting thiopurines. The TPMT activity was determined at inclusion (>5 U/mL required). Azathioprine metabolites [6TGN, 6-methyl-mercaptopurine ribonucleotides (6MMP), and 6TGN/6MMP and 6TGN/TPMT ratios] were periodically monitored during steroid tapering and after withdrawal for 6 months or until a new flare occurred. RESULTS: A total of 113 patients were analysed (62% clinical response). Areas under the receiver operating characteristic (ROC) curve (AUC) relating clinical response and metabolite levels at 2, 4 and 6 months after steroid withdrawal were less than 0.7. The AUCs relating final response and initial TPMT activity or metabolite concentrations at 2, 4, 8 and 16 weeks after starting thiopurines were less than 0.7. No cut-off point with worthwhile sensitivity/specificity was found. Eight (7%) patients developed thiopurine-related toxicity that could not be linked to TPMT activity or 6TGN levels. CONCLUSIONS: Our results do not support determination of TPMT activity or 6TGN concentrations to predict treatment outcome, and no useful serum metabolites threshold value to adjust the drug's dose was identified.


Assuntos
Azatioprina/sangue , Imunossupressores/uso terapêutico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Mercaptopurina/análogos & derivados , Mercaptopurina/administração & dosagem , Metiltransferases/sangue , Adolescente , Adulto , Idoso , Área Sob a Curva , Biomarcadores/metabolismo , Relação Dose-Resposta a Droga , Feminino , Nucleotídeos de Guanina/sangue , Humanos , Doenças Inflamatórias Intestinais/enzimologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Tionucleotídeos/sangue , Resultado do Tratamento , Adulto Jovem
3.
Rev Esp Enferm Dig ; 96(6): 379-81; 382-4, 2004 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-15230667

RESUMO

OBJECTIVE: To evaluate the efficacy and toxicity of infliximab for the treatment of fistulizing Crohn's disease. METHODS: Consecutive patients with fistulizing Crohn's disease receiving infliximab were prospectively enrolled. Partial response was defined as a reduction of 50% or more from base-line in the number of draining fistulae. Complete response was defined as the closure of all fistulae. The influence of different variables on the efficacy of infliximab was evaluated. RESULTS: 108 patients were included. The disease was inflammatory plus fistulizing in 18% and only fistulizing in 82%. After the third infusion of infliximab the response was partial in 26% and complete in 57%. Response (%) rates (partial/complete) depending on fistula location were: enterocutaneous (25/68%), perianal (35/60%), rectovaginal (36/64%), and enterovesical (20/40%). None of the studied variables (including concomitant immunosuppressive therapy) correlated with efficacy of infliximab in the multivariate analysis. Incidence of adverse effects (21%) depending on the dose of infliximab was: first dose (5.6%), second (7.4%), and third (11.1%). CONCLUSIONS: Infliximab is an efficacious treatment for fistulizing Crohn's disease. Partial response was achieved in approximately one third of the patients, and complete response in more than half. No studied variable was predictive of response. Adverse effects were relatively infrequent and mild.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Doença de Crohn/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Fístula Intestinal/tratamento farmacológico , Adulto , Doença de Crohn/complicações , Feminino , Humanos , Infliximab , Fístula Intestinal/etiologia , Masculino , Estudos Prospectivos , Resultado do Tratamento
5.
Biochem Biophys Res Commun ; 301(1): 152-8, 2003 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-12535655

RESUMO

Nucleolar segregation is the most striking cellular phenotypic feature of cold-acclimatized carp and depicts the cyclical reprogramming that the physiology of the fish undergoes between summer and winter, where a clear differential expression of some nucleolar related genes occurs. We characterized carp nucleolin, a nucleolar protein involved in multiple steps of ribosome biogenesis, and evaluated its expression upon fish acclimatization. We show that the carp cDNA deduced amino acid sequence exhibits the same tripartite structural organization found in other species. Nevertheless, we observed that nucleolin mRNA expression was strongly induced in the cold-adapted carp as was the nuclear protein content, assessed by immunocytochemistry in liver sections. The physiological up-regulation of nucleolin in the cold-acclimatized carp, where rRNA transcription and processing are depressed concomitantly with the nucleolus segregation, is consistent with the notion that nucleolin plays a fundamental role in repressing rRNA synthesis.


Assuntos
Aclimatação/fisiologia , Carpas/fisiologia , Nucléolo Celular/metabolismo , Regulação da Expressão Gênica , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/citologia , Encéfalo/metabolismo , Temperatura Baixa , DNA Complementar/genética , Fígado/citologia , Fígado/metabolismo , Masculino , Dados de Sequência Molecular , Fosfoproteínas/genética , Estrutura Terciária de Proteína , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Estações do Ano , Nucleolina
6.
Biol Res ; 34(1): 7-13, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11471523

RESUMO

We isolated and cloned a carp somatolactin SL DNA fragment, of which 78% of the nucleotides were identical to the corresponding salmon SL sequence. The results obtained upon Northern blot hybridization of carp pituitary RNA allowed the identification of two transcripts as described for other fish. When the content of SL transcripts in pituitary sections from summer- and winter-acclimatized carp was quantified by in situ hybridization assays, we found no significant differences between the two seasons. In salmonids, plasma SL reaches higher levels in summer than in winter in synchrony with the water temperature cycle; in the eurythermal carp, however, the complex adaptive responses imposed by seasonal environmental changes do not seem to include the regulation of the somatolactin detected with the probe used at the transcriptional level in pituitary glands.


Assuntos
Carpas/fisiologia , Glicoproteínas/genética , Hibridização In Situ/métodos , Hipófise/fisiologia , Hormônios Hipofisários/genética , Transcrição Gênica , Aclimatação/fisiologia , Animais , Sequência de Bases , Northern Blotting , Fragmentação do DNA , Proteínas de Peixes , Glicoproteínas/isolamento & purificação , Hormônios Hipofisários/isolamento & purificação , Salmão , Estações do Ano
7.
Mol Cell Biochem ; 227(1-2): 107-12, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11827160

RESUMO

The dramatic segregation of the nucleolar components in winter-acclimatized carp is the most striking cellular-phenotypical feature observed during the seasonal adaptation of this fish toward the circannual changes in its habitat. Our studies also show that the carp habitat temperature and photoperiod winter conditions provoke a remarkable reduction of both rRNA transcription and the processing of their precursors. To gain knowledge on the mechanisms involved in the regulation of nucleolar activity during the seasonal adaptation process, we studied the behavior of some genes, specifically snoRNA U3 and protein kinase CK2. Consistent with the reduction in the synthesis and processing of pre-rRNA observed during the cold season, the level of CK2beta expression decreases in winter when compared to that attained in summer. Similarly, in winter, liver and kidney cells contain lower levels of CK2beta subunit protein compared to summer. CK2 is associated with or modifies different factors and enzymes involved in the nucleolar activity; therefore, its higher or lower content could be part of the molecular mechanisms underlying the nucleolar seasonal changes that occur during the compensatory acclimatization process.


Assuntos
Carpas/genética , Carpas/metabolismo , Regulação Enzimológica da Expressão Gênica , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Serina-Treonina Quinases/genética , Animais , Western Blotting , Caseína Quinase II , Nucléolo Celular/metabolismo , Núcleo Celular/enzimologia , DNA Complementar/metabolismo , Imuno-Histoquímica , Rim/enzimologia , Luz , Fígado/enzimologia , Masculino , Modelos Moleculares , Peptídeos/química , Ligação Proteica , Estrutura Terciária de Proteína , Estações do Ano , Temperatura
8.
P R Health Sci J ; 19(2): 161-3, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10909713

RESUMO

Ethical issues pertaining research and counseling in nutritional sciences will be arising in this new century. This issue will be of great importance especially in the area of nutraceutical supplementation and disease (pharmacological nutrition). Steps to insure bioethical correctness are discussed in this paper.


Assuntos
Aconselhamento , Suplementos Nutricionais , Dietética/normas , Ética Profissional , Fenômenos Fisiológicos da Nutrição , Dietética/tendências , Previsões , Humanos , Pesquisa
9.
Biochem Biophys Res Commun ; 271(3): 735-40, 2000 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-10814532

RESUMO

Carp fish seasonal acclimatization induces a cyclical transcriptional modulation of several genes. Its most dramatic expression results in a concomitant structural rearrangement of the nucleolar components that phenotypically represents profound shifts in the level of ribosomal RNA synthesis. In connection with the recent studies that implicate CK2 in the control of rRNA synthesis in vertebrates, we characterized the cDNA of carp protein kinase CK2beta subunit and assessed its transcriptional behavior in winter- and summer-acclimatized fish. We found a remarkable differential gene expression of CK2beta subunit between summer- and winter-acclimatized carp which correlates with the modulatory pattern observed in rRNA transcription.


Assuntos
Aclimatação/fisiologia , Carpas/fisiologia , Proteínas Serina-Treonina Quinases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Caseína Quinase II , Linhagem Celular , Clonagem Molecular , Regulação Enzimológica da Expressão Gênica , Hibridização In Situ , Rim/enzimologia , Fígado/enzimologia , Dados de Sequência Molecular , Proteínas Serina-Treonina Quinases/metabolismo , RNA Mensageiro/metabolismo , RNA Ribossômico/genética , Estações do Ano , Alinhamento de Sequência
10.
P R Health Sci J ; 19(4): 389-92, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11293891

RESUMO

The use of alternative/complementary medicine has been increasing considerably. Conventional medicine must begin to address issues related to the use, safety, regulation, research and education of alternative/complementary medicine. Integrative medicine combines conventional medicine and alternative complementary practices. Integrative medicine is an innovative approach to medicine and medical education. It involves the understanding of the interaction of the mind, body and spirit and how to interpret this relationship in the dynamics of health and disease. Integrative medicine shifts the orientation of the medical practice from disease based approach to a healing based approach. It does not reject conventional medicine nor uncritically accepts unconventional practices. Integrative medicine is an effective, more fulfilling human approach to medicine based on the benefit of the patient by following good medicine practices in a scientific manner.


Assuntos
Terapias Complementares/educação , Prestação Integrada de Cuidados de Saúde/tendências , Educação Médica/tendências , Saúde Holística , Humanos , Porto Rico
11.
Nucleic Acids Res ; 27(23): 4533-40, 1999 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-10556307

RESUMO

Molecular mechanisms of ITS2 processing, a eukaryotic insertion between the 5.8S and LSU rRNA, remain largely elusive even in yeast. To delineate ITS2 structural and functional features which could be common to eukaryotes, we first produced phylo-genetically supported folding models in the vertebrate lineage, then tested them in deeper branchings and, more particularly, among yeasts. ITS2 comparisons between four Teleostei, a Chondrichthyes specimen and two jawless organisms have revealed a common folding architecture in four to five domains of secondary structure emerging from a preserved structural core. This folding, largely reminiscent of ITS2 architecture in mammals, is also preserved in amphibia and in chicken, despite dramatic sequence variations. Preferential conservation is located around a central loop and at the apex of a long stem in the ITS2 3'-half. Interestingly, these two independent structural features contain, respectively, the 3'-ends of the two transient rRNA precursors 8S and 12S RNA identified in mammals, suggesting a preservation of these intermediates of processing over the entire vertebrate group. Surprising similarities between the vertebrate ITS2 folding shape and that of invertebrates as well as protista have made intriguing the significant differences from the yeast model. A detailed comparative analysis including four relatively close species and Schizosaccharomyces pombe, a deep yeast branching, has revealed an alternative phylogenetically supported four-domain folding presenting strong similarities to the vertebrate model. Remarkably, the two best conserved regions of vertebrates have unambiguously preserved counterparts which are also sites for internal processing in yeast. Therefore, molecular mechanisms involved in ITS2 excision in vertebrates and yeast might be more closely related than currently believed and might require a very similar trans -acting machinery.


Assuntos
Conformação de Ácido Nucleico , RNA Ribossômico/química , Vertebrados/genética , Leveduras/genética , Animais , Sequência de Bases , Dados de Sequência Molecular , Homologia de Sequência do Ácido Nucleico
12.
J Cell Biochem ; 75(4): 598-609, 1999 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-10572243

RESUMO

A second Pit-1 gene in carp (Cyprinus carpio), including the complete structural gene and 1.1 kb of promoter region, was identified and completely sequenced. The exon-intron structure was determined, and reverse transcription-polymerase chain reaction (RT-PCR) experiments suggest that only one Pit-1 splice variant is present in carp pituitary. The effect of seasonal acclimatization on the extent of Pit-1 gene expression was studied in summer- and winter-acclimatized carp. Quantitative RT-PCR analysis revealed a clear increase of Pit-1 mRNA in the pituitaries from summer-acclimatized carp compared with the winter-adapted fish. In situ hybridization of pituitary gland sections with riboprobes representing the complete 5'-transactivating region of carp Pit-1 depicted a significantly higher Pit-1 mRNA level in the rostral pars distalis of the summer-acclimatized fish where prolactin is expressed in a manner that resembles the seasonal increase observed in the proximal pars distalis and the pars intermedia. The cell- and temporal-specific transcription of Pit-1 supports its role in the molecular mechanisms that underly the acclimatization process undergone by eurythermal fish as a result of the physical effects of seasonal changes on their habitat.


Assuntos
Carpas/genética , Carpas/metabolismo , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Hipófise/metabolismo , Estações do Ano , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Duplicação Gênica , Expressão Gênica , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Hibridização In Situ , Masculino , Dados de Sequência Molecular , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Temperatura , Fator de Transcrição Pit-1
13.
Biochem Mol Biol Int ; 45(4): 813-21, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9713706

RESUMO

We isolated a clone comprising four exons of the carp Pit-1 gene. Using synthetic oligonucleotide probes derived from the carp Pit-1 sequence Pit-1 expression was assessed by in situ hybridization in pituitary sections from summer- and winter-acclimatized carp. Semiquantitative analyses of the hybridization signals revealed a significant higher Pit-1 expression in the proximal pars distalis (PPD) and pars intermedia (PI) of the pituitary glands from summer-acclimatized carp, compared to the winter-acclimatized fish. In both adaptive states, relative to the PPD and PI, only a basal Pit-1 expression was detected in the rostral pars distalis. Thus, during seasonal acclimatization of an eurythermal fish, Pit-1 seems to be involved in the mechanisms that underlie the compensatory response.


Assuntos
Aclimatação , Carpas/fisiologia , Proteínas de Ligação a DNA/genética , Expressão Gênica , Hipófise/metabolismo , Fatores de Transcrição/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Carpas/genética , Clonagem Molecular , Biblioteca Genômica , Hibridização In Situ , Masculino , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Adeno-Hipófise/metabolismo , Estações do Ano , Fator de Transcrição Pit-1
15.
Bull Am Acad Psychiatry Law ; 22(1): 109-26, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8193382

RESUMO

Core concepts and selected research addressing the issue of patient-therapist sexual involvement (PTSI) are examined. Topics covered include the prevalence of PTSI, its suspected causes, the seduction process employed by offending therapists, the factors involved in patient's vulnerability, the mechanisms by which patients are damaged by PTSI, the types of harm caused to patients, the treatment of patients after PTSI, and the prevention of PTSI. The need to expand empirical research in all aspects of PTSI from the patient as well as from the therapists' perspective is strongly emphasized.


Assuntos
Pacientes/psicologia , Relações Médico-Paciente , Má Conduta Profissional , Comportamento Sexual , Humanos , Psiquiatria/legislação & jurisprudência , Psiquiatria/normas , Valores Sociais
16.
FEMS Microbiol Lett ; 115(2-3): 131-6, 1994 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-8138127

RESUMO

By means of a one-step one-tube extraction from less than 1 mg of tissue it is possible to identify, via the polymerase chain reaction, Renibacterium salmoninarum in salmon with bacterial kidney disease. A 149-bp DNA sequence unique to R. salmoninarum was specifically amplified and its nature confirmed by Southern hybridization using a non-isotopically labelled probe. The sensitivity of the approach allowed the detection of 22 R. salmoninarum cells. The procedure was successfully applied in the identification of the causative agent of bacterial kidney disease in kidney tissue from infected fishes.


Assuntos
Bacilos Gram-Positivos Asporogênicos/isolamento & purificação , Infecções por Bactérias Gram-Positivas/veterinária , Nefropatias/veterinária , Reação em Cadeia da Polimerase/métodos , Salmonidae/microbiologia , Animais , Sequência de Bases , DNA Bacteriano/genética , Doenças dos Peixes/diagnóstico , Bacilos Gram-Positivos Asporogênicos/genética , Infecções por Bactérias Gram-Positivas/diagnóstico , Infecções por Bactérias Gram-Positivas/genética , Dados de Sequência Molecular , Sensibilidade e Especificidade
17.
World J Microbiol Biotechnol ; 10(2): 149-53, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24420936

RESUMO

To obtain specific DNA probes for the identification of the fish pathogen, Renibacterium salmoninarum, a discriminatory recombinant DNA library was constructed using selective fragments of the bacterial genome. Three renibacterial clones, pMAM29, pMAM46 and pMAM77, containing 149, 73, and 154 bp respectively, were isolated and characterized. The specificity of the probes was confirmed by dot-blot and Southern hybridization analyses. Bacterial hybridization experiments revealed that pMAM29 discriminates the R. salmoninarum genome from that of other fish pathogens such as Aeromonas salmonicida, Yersinia ruckeri, Flexibacter columnaris, Lactobacillus piscicola, Vibrio ordalii, Vibrio anguillarum and Aeromonas hydrophila. Thus, this probe may provide a new means to diagnose bacterial kidney disease in asymptomatic fish and ova.

18.
Comp Biochem Physiol Comp Physiol ; 106(4): 677-82, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7906626

RESUMO

1. The intestinal absorption of insulin in carps was assessed examining the transepithelial passage of ingested gold-labeled hormone by electron microscopy. Insulin transfer occurred mainly through the intercellular spaces between the enterocytes. 2. When reaching the lamina propria, the gold-labeled hormone gathered predominantly around the granules of the granular cells, and therefore can enter the circulatory system via the blood capillaries which are found in close contact with these cells. 3. Winter-acclimatized carp were also capable of internalizing the hormone when fed with insulin. 4. Furthermore, the absorbed hormone revealed full activity in regard to the observed changes in the ultrastructure of the liver cells of the treated cold-adapted fish. 5. The fish ingesting the hormone underwent the same type of hepatic ultrastructure reprogramming observed when winter-acclimatized carps are injected intraperitoneally with insulin, i.e. conversion to a phenotype corresponding to hepatocytes from summer-adapted carp. 6. The oral absorption of insulin by winter-acclimatized fish and its effect in reversing the cold-adaptive state might be useful for the fish culturing industry.


Assuntos
Aclimatação/fisiologia , Carpas/fisiologia , Insulina/farmacologia , Fígado/ultraestrutura , Administração Oral , Animais , Carpas/anatomia & histologia , Temperatura Baixa , Feminino , Coloide de Ouro , Absorção Intestinal , Fígado/efeitos dos fármacos , Fígado/fisiologia , Masculino , Microscopia Eletrônica
19.
Cell Mol Biol Res ; 39(7): 665-74, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-7519943

RESUMO

During seasonal acclimatization of eurythermal fish, the nucleolus of the hepatocyte undergoes ultrastructural reprogramming. In winter acclimatized carp, the nucleolar components are segregated, a condition that suggests a decreased transcription of rRNA. The same nucleolar reorganization was observed when pituitary cells from winter- and summer-acclimatized carp were examined. In situ analyses of nucleolar RNA revealed a marked lowering of RNA content in the segregated nucleoli. Accordingly, in vitro synthesis of RNA was shown to be significantly lower in pituitary tissue from cold-acclimatized fish where precursor accumulated. Conversely, in pituitary tissue from summer-adapted fish the rate and extent of synthesis and of rRNA processing was notably higher. The involvement of pre-rRNA processing events during seasonal acclimatization was corroborated by the strong differences of U3 RNA content detected by in situ hybridization in pituitary cells from summer- and winter-fish. When RNA polymerase I activity from both acclimatized states were assayed, no differences were detected. Thus, it appears that in fish RNA polymerase I itself does not play an important role in the control of nucleolar gene expression and the nucleolar gene expression reprogramming that the seasonal rearrangement represents might involve, among the many nucleolar-specific proteins, transcription factors.


Assuntos
Aclimatação , Carpas/fisiologia , Nucléolo Celular/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Regulação da Expressão Gênica , Fígado/metabolismo , Hipófise/metabolismo , RNA/biossíntese , Transcrição Gênica , Animais , Sequência de Bases , Nucléolo Celular/ultraestrutura , Sequência Consenso , Hibridização In Situ , Fígado/ultraestrutura , Masculino , Dados de Sequência Molecular , Hipófise/ultraestrutura , RNA Nuclear Pequeno/biossíntese , Estações do Ano , Temperatura , Truta/fisiologia , Xenopus laevis
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